1. Field of the Invention
The present invention relates to a numerical controller which has a function of automatically selecting a parameter based on a size of a machining area.
2. Description of the Related Art
Various prior art techniques for automatically setting and adjusting a parameter of a numerical controller, which controls a machine tool, so as to set a parameter suitable for the machine tool are well known.
For example, Japanese Patent Application Laid-Open No. 10-080055 (JP 10-080055, A) discloses a technique in which a motor temperature after set time is estimated based on a measured motor temperature and when the estimated motor temperature exceeds a threshold value, at least one of lowering the maximum speed of the motor, increasing an acceleration/deceleration time constant, reducing an override value, and increasing operation stop time is performed so as to prevent overheat of the motor.
Further, Japanese Patent Application Laid-Open No. 2000-271836 (JP 2000-271836, A) discloses a technique in which acceleration/deceleration time constants in rapid traverse and cutting feed of a feed axis and data on a tolerable predetermined amount of heat generation are preliminarily set and the acceleration/deceleration time constants are adjusted in the case where an amount of heat generation calculated based on data in an operation based on a numerical control program exceeds the tolerable predetermined amount of heat generation.
Furthermore, Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2013-525894 (JP 2013-525894, A) discloses a technique in which control is performed by using a data set in which respective tools, tool paths, and machining parameters are stored for all of various manufacturable products. Furthermore, Japanese Patent Application Laid-Open No. 06-142954 (JP 06-142954, A) discloses a technique in which machining data, in which a machining condition corresponding to each machining shape of a member to be machined is recorded, is prepared and machining is performed based on the machining data corresponding to a machining shape.
However, in both of the techniques disclosed in JP 10-080055, A and JP 2000-271836, A, a parameter is adjusted based on information obtained when a control axis operates (a motor temperature or an amount of heat generation) and thus, these techniques are based on the premise that a machine tool is already operable. Therefore, these techniques are not applicable to automatic adjustment of a parameter in starting-up of a machine tool.
Further, in the techniques disclosed in JP 2013-525894, A and JP 06-142954, A, a parameter is switched based on a numerical control program prepared for each product and thus, these techniques are based on the premise that a machine tool is already operable. Therefore, these techniques are not applicable to automatic adjustment of a parameter in starting-up of a machine tool.